Abstract: This surface potential sensor is provided with an electret electrode (28), which is configured of a metal film (26) and an electret film (27), said electret electrode being provided on an upper surface of a diaphragm (25) of a semiconductor substrate. Four piezoresistors (29a, 29b, 29c, 29d) are formed on the diaphragm (25), and a distortion quantity detecting unit (32) is configured by forming a bridge circuit using the piezoresistors. Since an electrostatic force that operates between an object and the electret electrode (28) changes corresponding to potential of the object, and the electret electrode (28) warps corresponding to the change, the potential of the object can be detected by measuring a distortion quantity of the electret electrode (28) by means of the distortion quantity detecting unit (32). Consequently, not only the potential of the object but also a polarity thereof can be detected with reduced size and high sensitivity.

Abstract: This surface potential sensor is provided with an electret electrode (28), which is configured of a metal film (26) and an electret film (27), said electret electrode being provided on an upper surface of a diaphragm (25) of a semiconductor substrate. Four piezoresistors (29a, 29b, 29c, 29d) are formed on the diaphragm (25), and a distortion quantity detecting unit (32) is configured by forming a bridge circuit using the piezoresistors. Since an electrostatic force that operates between an object and the electret electrode (28) changes corresponding to potential of the object, and the electret electrode (28) warps corresponding to the change, the potential of the object can be detected by measuring a distortion quantity of the electret electrode (28) by means of the distortion quantity detecting unit (32). Consequently, not only the potential of the object but also a polarity thereof can be detected with reduced size and high sensitivity.

Abstract: An embodiment of the invention provides a display filter, in which plural design patterns are independently illuminated and displayed and aesthetics is not lost during turn-off of a source light beam, and a display module provided with the display filter. The display filter includes plural design pattern filters and a blindfold filter. The blindfold filter is disposed on a visibility side opposite a light source, and the blindfold filter transmits source light beams having specific wavelength ranges which are transmitted through the design patterns respectively, and the blindfold filter absorbs light beams having wavelength ranges out of the specific wavelength ranges. Therefore, the blindfold filter is provided, whereby the design pattern can be illuminated and displayed when the light source is lit on, and the design patterns hardly visible to prevent deterioration of the aesthetics compared with a conventional technique when only an outer peripheral light beam exists while the light source is turned off.

Abstract: An intake system construction for an internal combustion engine having a generally straight first intake port, a generally helical second intake port, both intake ports opening to one combustion chamber, and a common intake passage for supplying fuel-air mixture to the two intake ports. A control valve is fitted in the first intake port for selectively throttling the first intake port at low load operation of the engine, and a deflection valve is fitted in the commmon intake passage for selectively constricting intake flow through the common intake passage to deflect the flow toward the second intake port and away from the first intake port at low load operation of the engine, so that fuel accumulation on the cotrol valve closed at low load operation of the engine is avoided.

Abstract: An air-fuel mixture intake system of an internal combustion engine includes a helical passage and a straight passage for conducting the air-fuel mixture to an intake port of the engine, the straight passage being selectively closed by a straight passage switchover control valve. A control device for operating the straight passage switchover control valve comprises a valve drive system including a diaphragm adapted to be actuated by intake vacuum of the engine, a vacuum switching valve for selectively either connecting the diaphragm to the intake manifold or releasing the diaphragm to the atmosphere, and a one way valve provided between the vacuum switching valve and the intake manifold so as to hold vacuum on one side thereof toward the diaphragm.

Abstract: A method of reducing the amount of nitrogen oxides (NOx) in an internal combustion engine in which the air/fuel ratio is controlled higher than a theoreticl air/fuel ratio during normal operation of a vehicle, characterized in that the air/fuel ratio is controlled lower than the theoretical air-fuel ratio for a predetermined period of time during acceleration from the start of acceleration, the control being effected by means for detecting an accelerated state of the vehicle, means for measuring the lapse of time during acceleration from the start of acceleration and means for performing an acceleration increment correction upon detection of acceleration.